Email templates not updating

I have a strange problem: I am using ActionMailer via ar_mailer to mail
out some multi-part email with templates and it's working just fine.
But, if I make a change to the templates, new email generated uses the
old template. I've looked at all the moving parts and they seem to be in
order—even tried restarting the httpd process thinking passenger wasn't
listening to the touch /tmp/restart.txt deal.

Does someone know if there's some weird caching thing with mail
templates? And, how to clear that cache out? Any clues on how to go
about troubleshooting this further? TIA for any help.

I'm using Rails 2.2.3, production environment on a RHEL machine, apache
+ passenger.